Search Results (99)

The global cement industry remains a significant contributor to carbon dioxide (CO₂) emissions, prompting substantial research efforts toward sustainable construction materials. Lithium slag (LS), a by-product of lithium extraction, has attracted attention as a supplementary cementitious material (SCM). This review synthesizes experimental findings on LS replacement levels, fresh-state behavior, mechanical performance (compressive, tensile, and flexural strengths), time-dependent deformation (shrinkage and creep), and durability (sulfate, acid, abrasion, and thermal) of LS-modified concretes. Statistical analysis identifies an optimal LS dosage of 20–30% (average 24%) for maximizing compressive strength and long-term durability, with 40% as a practical upper limit for tensile and flexural performance. Fresh-state tests show that workability losses at high LS content can be mitigated via superplasticizers. Drying shrinkage and creep strains decrease in a dose-dependent manner with up to 30% LS. High-volume (40%) LS blends achieve up to an 18% gain in 180-day compressive strength and >30% reduction in permeability metrics. Under elevated temperatures, 20% LS mixes retain up to 50% more residual strength than controls. In advanced systems—autoclaved aerated concrete (AAC), one-part geopolymers, and recycled aggregate composites—LS further enhances both microstructural densification and durability. In particular, LS emerges as a versatile SCM that optimizes mechanical and durability performance, supports material circularity, and reduces the carbon footprint. Full article

The present article aims to develop a technological scheme for processing zinc ferrite residue, which typically forms during the leaching of zinc calcine. This semi-product is currently processed through the Waelz process, the main disadvantage of which is the loss of precious metals with the Waelz clinker. The experimental results of numerous experiments and analyses have verified a technological scheme including the following operations: sulfuric acid leaching of zinc ferrite residue under atmospheric conditions; autoclave purification of the resulting productive solution to obtain hematite; chloride leaching of lead and silver from the insoluble residue, which was produced in the initial operation; and cementation with zinc powder of lead and silver from the chloride solution. Utilizing such an advanced methodology, the degree of zinc leaching is 98.30% at a sulfuric acid concentration of 200 g/L, with a solid-to-liquid ratio of 1:10 and a temperature of 90 °C. Under these conditions, 96.40% Cu and 92.72% Fe form a solution. Trivalent iron in the presence of seeds at a temperature of 200 °C precipitates as hematite. In chloride extraction with 250 g/L NaCl, 1 M HCl, and a temperature of 60 °C, the leaching degree of lead is 96.79%, while that of silver is 84.55%. In the process of cementation with zinc powder, the degree of extraction of lead and silver in the cement precipitate is 98.72% and 97.27%, respectively. When implementing this scheme, approximately 15% of the insoluble residue remains, containing 1.6% Pb and 0.016% Ag. Full article

In wet subtropical environments, perennial groundcovers are common in horticultural plantations to protect the soil from erosion. However, there has been little investigation into whether seeding annual cover crops into the perennial groundcovers provides additional soil services including carbon and nutrient cycling in these systems. To investigate this, farmer participatory field trials were conducted in commercial avocado, macadamia, and coffee plantations in the wet Australian subtropics. Cover crops were direct-seeded into existing inter-row groundcovers in winter (cool season cover crops), and into the same plots the following summer (warm season cover crops). Inter-row biomass was quantified at the end of winter and summer in the control (no cover crop) and cover crops treatments. Soil carbon and nutrient cycling parameters including hot water extractable carbon, water soluble carbon, autoclavable citrate-extractable protein and soil enzyme activities were quantified every two months from early spring (September) 2021 to late autumn (May) 2022. Seeded cover crops produced 500 to 800 kg ha⁻¹ more total inter-row biomass over winter at the avocado coffee sites, and 3000 kg ha⁻¹ biomass in summer at the coffee site. However, they had no effect on biomass production in either season at the macadamia site. Soil functional parameters changed with season (i.e., time of sampling), with few significant effects of cover crop treatments on soil function parameters across the three sits. Growing a highly productive annual summer cover crop at the coffee site led to suppression and death of perennial groundcovers, exposing bare soil in the inter-row by 3 weeks after termination of the summer cover crop. Annual cover crops seeded into existing perennial groundcovers in tree crop systems had few significant impacts on soil biological function over the 12-month period, and their integration needs careful management to avoid investment losses and exacerbating the risk of soil erosion on sloping lands in the wet subtropics. Full article

Industrial technologies for processing tungsten concentrates using soda roasting or autoclave leaching are based on the production of alkaline sodium tungstate solutions that contain impurities such as silicon, phosphorus, arsenic, and others. The purification of these solutions from impurities requires the neutralization of excess soda or alkali with inorganic acids, which leads to the formation of chloride and sulfate effluents that are subsequently discharged into waste repositories. An analysis was carried out on existing methods for the production and processing of sodium tungstate solutions using HNO₃ and NH₃, as well as extraction and sorption techniques involving anion exchange resins. Currently, processes such as nanofiltration, reverse osmosis, and electrodialysis are being applied for water purification and the treatment of sulfate and chloride effluents. These processes employ various types of industrially manufactured membranes. For the purpose of electrodialysis, a two-compartment electrodialyzer setup was employed using cation-exchange membranes of the MK-40 (Russia) and EDC1R (China) types. The composition and structure of sodium tungstate, used as the starting reagents, were analyzed. Based on experiments conducted on a laboratory-scale unit with continuous circulation of the catholyte and anolyte, dependencies of various parameters on current density and process duration were established. Stepwise changes in the anolyte pH were recorded, indirectly confirming changes in the composition of the Na₂WO₄ solution, including the formation of polytungstates of variable composition and the production of H₂WO₄ via electrodialysis at pH < 2. The resulting tungstic acid solutions were also analyzed. The conducted studies on the processing of sodium tungstate solutions using electrodialysis made it possible to obtain alkaline solutions and tungstic acid at a current density of 500–1500 A/m², without the use of acid for neutralization. Yellow tungstic acid was obtained from the tungstic acid solution by evaporation. Full article

Investigating viable processes for the use of lignocellulosic biomass in clean fuels and high-value-added chemical products is essential for sustainable development. Large amounts of lignin are available every year as by-products of the paper and biorefinery industries, causing a series of problems, particularly environmental ones. Its structure and composition make lignin compatible with the concept of sustainability, since it can be used to produce new chemical products with high added value. As such, this study aims to extract lignin from green coconut fiber (LIG), with the subsequent impregnation of a sodium-octanoate-based surfactant (LIG-SUR), and determine its applicability as an adsorbent for removing copper ions from synthetic waste. To this end, the green coconut fiber lignocellulosic biomass was initially subjected to alkaline pre-treatment with 2% (w/v) sodium hydroxide in an autoclave. Next, the surface of the lignin was modified by impregnating it with sodium octanoate, synthesized from the reaction of octanoic acid and NaOH. The physical and chemical traits of the lignin were studied before and after surfactant impregnation, as well as after copper ion adsorption. The lignin was analyzed by X-ray fluorescence (XRF), Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). The adsorption tests were carried out using lignin pre-treated with surfactant in a batch system, where the effects of pH and adsorbent concentration were investigated. XRF and SEM analyses confirmed surfactant impregnation, with Na₂O partially replaced by CuO after Cu²⁺ adsorption. FTIR analysis revealed shifts in O–H, C–H, C=O, and C=C bands, indicating electrostatic interactions with lignin. Adsorption kinetics followed the pseudo-second-order model, suggesting chemisorption, with equilibrium reached in approximately 10 and 60 min for LIG-SUR and LIG, respectively. The Langmuir model best described the isotherm data, indicating monolayer adsorption. LIG-SUR removed 91.57% of Cu²⁺ and reached a maximum capacity of 30.7 mg·g⁻¹ at 25 °C and a pH of 6. The results of this research showed that pre-treatment with NaOH, followed by impregnation with surfactant, significantly increased the adsorption capacity of copper ions in solution. This technique is a viable and sustainable alternative to the traditional adsorbents used to treat liquid waste. In addition, by using green coconut fiber lignin more efficiently, the research contributes to adding value to this material and strengthening practices in line with the circular economy and environmental preservation. Full article

The response surface methodology (RSM) is utilized to construct a corrosion prediction model for steel pipelines for underground gas storage (UGS). Four key corrosion-influencing factors—the CO₂ partial pressure, Cl⁻ concentration, temperature, and flow rate—are identified by investigating the operating parameters of 14 UGS extracted pipelines (Nos. S1–S14) in China. Based on the operating parameters, 29 sets of high-temperature and high-pressure autoclave corrosion tests are designed and carried out. A quadratic regression equation model for corrosion rate prediction is fitted using the data from the corrosion test results. The p-values of the model’s four influencing factors are <0.01, indicating that the influencing factors are significant and reasonable. The F-value of the model is greater than the critical value, and the noise probability p-value is <0.01, indicating that the model has good fitness. The determination coefficient R² of the model is 0.9753, which is close to 1. Therefore, the observed value and the response value of the model are obviously correlated: i.e., the model has a high degree of truth. The model is used to predict the corrosion rate of 14 UGS pipelines: S3 and S14 are severely corroded, while the others are moderately corroded. Full article

This study evaluated Lolium perenne press juice as a sustainable substrate for Single-Cell Protein (SCP) production using Kluyveromyces marxianus. Key fermentation parameters were systematically optimized, including microbial reduction, dilution ratios, temperature, and nutrient supplementation. Pasteurization at 75 °C preserved essential nutrients better than autoclaving, resulting in a 27.8% increase in biomass yield. A 1:2 dilution of press juice enhanced fermentation efficiency, achieving 20.2% higher biomass despite a lower initial sugar content. Cultivation at 30 °C enabled sustained substrate utilization and outperformed 40 °C fermentation, increasing final biomass by 43.4%. Nutrient supplementation with yeast extract, peptone, and glucose led to the highest biomass yield, with a 71% increase compared to unsupplemented juice. Press juice from the tetraploid variety, Explosion, consistently outperformed the diploid Honroso, especially when harvested early, reaching up to 16.62 g·L⁻¹ biomass. Early harvests promoted faster growth, while late harvests exhibited higher biomass yield coefficients due to improved sugar-to-biomass conversion. Compared to a conventional YM medium, fermentation with L. perenne press juice achieved up to a threefold increase in biomass yield. These findings highlight the potential of grass-based substrates for efficient SCP production and demonstrate how agricultural parameters like variety and harvest timing influence both quantity and quality. The approach supports circular bioeconomy strategies by valorising underutilized biomass through microbial fermentation. Full article

The present study aims to evaluate the mechanical properties, colorimetric characteristics, and decay resistance of Pinus elliottii woods treated with oxides synthesized via green chemistry. For this purpose, an aqueous extract from Eucalyptus dunnii leaves was used to synthesize particles based on copper- and zinc-based oxides, as well as a binary oxide system (CuO/ZnO). Sodium polyacrylate was employed as a dispersant, impregnating the oxides into the wood through a horizontal autoclave using a modified Bethell process, assisted by a compressor, applying a pressure of 0.8 MPa for 30 min. The exposure to weathering aging did not significantly alter the mechanical properties of the samples, but it caused the leaching of particles from the treated wood surface, as shown by colorimetric results. Regarding the decay resistance, the copper-based oxide proved to be the most effective treatment against Trametes versicolor (a white-rot fungus), reducing mass loss down to 1.2%. The CuO/ZnO formulation reduced the mass loss caused by Gloeophyllum trabeum to 1.1%, while the zinc oxide showed minimal efficacy. Thus, oxides synthesized via green chemistry using aqueous leaf extracts and mild thermal conditions for synthesis and calcination proved effective in enhancing the wood resistance against biotic deterioration agents. Full article

This study explores both pyrometallurgical and hydrometallurgical methods for decarbonizing and recovering valuable metals from bauxite residue, with hydrogen plasma reduction and direct acid leaching as the primary approaches. The goal is to offer innovative techniques for extracting metals from bauxite residue, a by-product of the Bayer process, which cannot be disposed of in an environmentally sustainable manner. Additionally, reducing the volume of bauxite residue through combined treatments is a key objective. In contrast to traditional carbon-based reductive melting, which generated significant CO₂ emissions, hydrogen is now being investigated as a cleaner alternative. Through hydrogen plasma reduction, approximately 99.9% of iron is recovered as crude metallic iron, which can be easily separated from the slag containing other valuable metals. Thermochemical analysis was used to predict slag formation and chemical analysis of slag during hydrogen reduction. To further recover metals like aluminum and titanium, the slag is subjected to sulfuric acid leaching under high-pressure of oxygen in an autoclave avoiding silica gel formation. The results demonstrated a leaching efficiency of 93.21% for aluminum and 84.56% for titanium, using 5 mol/L sulfuric acid at 150 °C, with almost complete iron recovery. Assisted ultrasound leaching of slag with sulphuric acid under atmospheric pressure leads to 54% leaching efficiency of titanium. Full article

Intensive agricultural management affects the physical, chemical, and biological properties of soil, potentially contributing to a decrease in soil carbon storage. In this study, the effects of soil management intensity on soil organic carbon (SOC) content and its labile fractions, i.e., water-soluble organic carbon (OC-sol) and permanganate oxidizable carbon (POXC), were evaluated in a volcanic-ash-derived soil (Andisol) with a very high soil organic matter (SOM) content (>20%). These indicators were associated with water-stable aggregates (WSAs) and biological indicators, namely, earthworm density, cellulase activity, and autoclaved-citrate-extractable (ACE) proteins, related to the decomposition of SOM and its physical protection. The conditions evaluated were secondary native forest (SF), naturalized grassland (NG), no-till (NT), and conventional tillage (CT), considering the last item to be representative of a higher agriculture management intensity. Soil samples were collected by horizon. The SF and NG soil showed higher contents of SOC, OC-sol, and POXC. When comparing the evaluated annual cropping systems, NT showed higher values than CT (p < 0.05) in the first horizon (Hz1), while similar values were found at deeper horizons. The highest cellulase activity, ACE protein levels, and earthworm densities were found in NG and SF. NT also showed significantly higher levels of the aforementioned factors than CT (p < 0.05). A positive and significant relationship was found between the SOC content and WSA (R² = 0.76; p < 0.05) in the whole profile and between POXC and WSA for Hz1 (R² = 0.67; p < 0.05). Soil C storage was affected by the intensity of agricultural management, mainly because of the effect of tillage on structural stability, considering that biological activity synthesizes compounds such as enzymes and proteins that react and adhere to the mineral fraction affecting aggregate stability. The C content stored in the soil is consequently a key indicator with which to regulate SOM and protect SOC. Full article

Background/Objectives: Natural antibacterial agents, such as essential oils, can potentially be used for endodontic disinfection with less toxicity than other available irrigants such as sodium hypochlorite (NaOCl) and chlorhexidine (CHX). Benefect^TM is a formulation of essential oils with broad antibacterial spectrum efficacy. This study aims to compare the antibacterial efficacy of Benefect^TM to 6% NaOCl and 2% CHX irrigant solutions against multiple endodontic pathogens. Methods: The study utilized 100 extracted human single-canal permanent teeth. Samples were decoronated, instrumented, and autoclaved. The teeth were infected with Streptococcus mutans, Enterococcus faecalis, Actinomyces naeslundii, or Porphyromonas gingivalis for 6–24 h. The teeth were divided into four groups according to the irrigant solution used. Contact with each irrigant was maintained for 12 min. The antibacterial efficacy of each treatment was calculated relative to viable bacteria recovered after saline treatment. Statistical analysis was performed using Student’s t-test. Results: All S. mutans samples treated with NaOCl, CHX, and Benefect^TM showed a complete absence of bacterial colonies when compared to saline (>99.9% killing). The E. faecalis, A. naeslundii, and P. gingivalis samples treated with all tested irrigants showed at least 99% antibacterial killing activity. There was no statistical difference in killing between these three antimicrobial treatments. Conclusions: Benefect^TM botanical disinfectant has comparable antibacterial efficacy to NaOCl and CHX against S. mutans, E. faecalis, A. naeslundii, and P. gingivalis. Full article

Bos frontalis (Mithun) and Bos grunniens (yak) are crucial to the culture, food security, and economy of Southeast Asia, especially in India and China, respectively. Their genetic closeness to Bos indicus (indicine cattle) and Bos taurus (taurine cattle) necessitates precise methods for meat origin authentication. This study introduces a DNA-based technique to distinguish Mithun and yak species using the alkaline lysis (AL) protocol for DNA extraction, followed by species-specific polymerase chain reaction (PCR) to amplify unique mitochondrial D-loop regions, yielding 489 bp and 422 bp amplicons, respectively. The AL-PCR method showed high specificity for both species, with no cross-amplification with other related species. The method’s effectiveness was validated across various sample preparations, including raw, cooked, autoclaved, microwaved, and fried samples. The AL-PCR assay is highly sensitive, detecting as little as 1 pg of Mithun DNA and 100 pg of yak DNA, and can identify down to 0.1% of these species in binary mixtures. This approach is rapid and cost-effective, offering significant benefits for consumer protection, promoting Mithun and yak farming, and addressing food safety and traceability issues. Full article

Animal manure is a desirable fertilizer because of its rich nitrogen, but it also contains a large and diverse reservoir of antimicrobial resistance (AMR) genes (ARGs). To reduce this AMR reservoir, five treatments (passive aeration, forced aeration, static or anaerobic incubations, autoclaving) were assessed for their impact on the poultry litter resistome. Bacterial DNA was extracted from the litter and the qPCR-estimated copy number of 16S rrs, class1 integrons (intI1) and associated resistance genes (aadA, sul1). Then, 16S amplicon metagenomic sequencing was used to determine community diversity and composition. Depending on incubation conditions, class 1 integrons and their associated ARGs were reduced by 0.5 to 1.0 Log₁₀/g poultry litter. Only autoclaving reduced integrons and associated AMR genes by three Log₁₀. Changes in AMR abundance reflected fluctuations in litter bacteriome composition at the family, genus, and sequence variant level. There was a negative correlation between class 1 integron and AMR genes, with genera belonging to Actinobacteria, Firmicutes, and Proteobacteria phyla. While these poultry litter treatments failed to reduce AMR abundance, aerobic and anaerobic treatments reduced taxons that contained pathogenic species. The approach to remediating resistance in poultry litter may be more effective if is focused on reducing bacterial pathogens. Full article

The quest for natural preservation systems is on the rise due to health hazards associated with synthetic preservatives. The current study explores a significant research gap by investigating the antifungal potential of Eucalyptus citriodora essential oil (EO) and modified potato peel starch (M-PPS)-based coatings to control the fungal contamination in peanut kernels, providing a sustainable food preservation system. Potato peel starch was extracted by water steeping and modified by autoclaving. E. citriodora EO was extracted from leaves by steam distillation and chemically characterized using a gas chromatography mass spectrometer (GC-MS). The antifungal potential of EO was evaluated by radial growth inhibition assay (RGI). EO completely inhibited the growths of Penicillium griseofulvum and Aspergillus niger at a concentration of 3.125 µL/mL, which was marked as the minimum inhibition concentration (MIC). EO induced cellular leakage from fungal cells, and hyphae became pitted, indicating the strong antifungal potential of EO. EO (2 ×MIC)-treated rice seeds showed complete inhibition of A. niger after 7 days of incubation, and in the control treatments, all the rice seeds were contaminated (100% contamination index). M-PPS and EO-based coatings controlled the growth of P. griseofulvum in peanut kernels. After incubation for 7 days, control treatments were fully contaminated with fungal growth, whereas the M-PPS and EO-based coatings restricted the growth of fungi in peanut kernels. The M-PPS and EO-based preservation system can be used for the preservation of perishable food products. Full article

This study investigates the extraction, characterization, and cosmetic application of silk sericin, a protein derived from Bombyx mori silkworm cocoons, with a focus on its potential in sustainable and biodegradable cosmetic formulations. Sericin was extracted using a high-temperature, high-pressure autoclave degumming method and spray-dried into a stable powder. The molecular weight distribution of sericin was analyzed, revealing fractions ranging from 10 to 37 kDa in Elution 1A and 25–40 kDa in Elution 1B. Electrospinning of sericin led to increased β-sheet content compared to raw sericin, as shown by secondary structure analyses. The electrospun sericin was then blended with gelatin to enhance mechanical strength and stability, resulting in robust films suitable for cosmetic applications. These films were developed into eye contour patches designed to deliver moisturizing, elasticizing, and smoothing effects. The efficacy of the patches was evaluated in 20 participants, showing increased skin elasticity (+35.1%) and smoothness (R_a: −30.7%, R_z: −26.6%), though a decline in hydration was observed, potentially indicating opportunities for further optimization. Full article